How to upload an attachment to a work item via REST API

			def upload_attachment(self, file_location, work_item_number):
		
			        
		
			        # First get the work item details
		
			        filters = {'oslc_cm.properties': 'oslc_cmx:project'}
		
			        attachment_work_item = self.get_work_item(work_item_number, filters=filters)
		
			        if attachment_work_item is None:
		
			            raise Exception("Error: Work item to add link to could not be found")
		

			        work_item_project_area = attachment_work_item['oslc_cmx:project']['rdf:resource'].rsplit('/', 1)[1]
		

			        file = open(file_location, 'rb')
		
			        file_short_name = os.path.basename(file.name)
		
			        files = {'attach': (file_short_name, file,
		
			                            'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet')}
		

			        # This is really important for requests to work out what kind of content it is
		
			        if self.session.headers.__contains__('Content-Type'):
		
			            self.session.headers.__delitem__('Content-Type')
		

			        # Not a 100% sure what is the category here???? Seems to be constant for now through
		
			        post_params = {"projectId": work_item_project_area,
		
			                       "multiple": "true",
		
			                       "category": "_IlAckNAwEeOaT8v4QaB0Wg"}
		
			        url = self._base_url + "/ccm/service/com.ibm.team.workitem.service.internal.rest.IAttachmentRestService/"
		

			        upload_response = self.session.post(url, files=files, params=post_params)
		
			        if not upload_response.ok:
		
			            raise Exception("A problem occurred in retrieving the work item: "
		
			                            + upload_response.reason + " - " + upload_response.url)
		

			        return upload_response.json()
		
	

This code uses the python requests library. You can then link the attachment to the work item. The key part here is the attachment UUID which is returned from in the above response.

			def add_attachment_link(self, work_item_number, attachment_uuid):
		

			        attachment_url = self._base_url + '/ccm/resource/itemOid/com.ibm.team.workitem.Attachment/' + attachment_uuid
		
			        attachment_get_repsonse = self._session_get(attachment_url)
		
			        attachment_get_repsonse_json = attachment_get_repsonse.json()
		
			        attachment_identifier = attachment_get_repsonse_json['dcterms:identifier']
		
			        attachment_description = attachment_get_repsonse_json['dcterms:description']
		

			        # May need to add some checking in here to make sure that the work item is not closed or something
		

			        self.session.headers.update({'Content-Type': 'application/json'})
		

			        payload = {'rdf:resource': self._base_url + '/ccm/resource/itemOid/com.ibm.team.workitem.Attachment/'
		
			                                   + attachment_uuid,
		
			                   'dcterms:title': attachment_identifier.__str__() + ": " + attachment_description,
		
			                   }
		
			        attachment_collection_url = self._base_url + "/ccm/oslc/workitems/" + work_item_number \
		
			                                    + "/rtc_cm:com.ibm.team.workitem.linktype.attachment.attachment"
		
			        update_response = self._session_post(attachment_collection_url, payload)
		

			        return update_response.json()
		
	

You should then have a link to your workitem.